1. Field of the Invention
This invention relates to medical imaging. More particularly, this invention relates to improvements in the identification of topologic features in cardiac ultrasound images.
2. Description of the Related Art
Ultrasound imaging is now well established as a modality for imaging the heart. For example, U.S. Pat. No. 6,066,096, whose disclosure is incorporated herein by reference, describes an imaging probe for volumetric intraluminal ultrasound imaging. The probe, configured to be placed inside a patient's body, includes an elongated body having proximal and distal ends. An ultrasonic transducer phased array is connected to and positioned on the distal end of the elongated body. The ultrasonic transducer phased array is positioned to emit and receive ultrasonic energy for volumetric forward scanning from the distal end of the elongated body. The ultrasonic transducer phased array includes a plurality of sites occupied by ultrasonic transducer elements.
However, many physicians find it difficult to interpret ultrasound images, which typically appear as a two-dimensional fan-shaped pattern. Although the physician knows what anatomical features should appear in a display produced by an ultrasound catheter, he may not be able to match these features with the bright and dark areas of the fan.
It has been proposed to improve medical image interpretation by superimposing images acquired by different modalities in registration. For example, U.S. Pat. No. 6,556,695, issued to Packer et al., suggests that a magnetic resonance image can be acquired, and then registered with a subsequently acquired electrical activation map or ultrasound image.